Field of the Invention
The present invention relates to a target substance capturing device that detects a target substance.
Description of the Related Art
As means to detect a target substance such as protein or a cell, or to measure the concentration, biosensors using a photonic crystal are known (for example, Non Patent Literature 1 (hereinafter, Prior Art 2)). The biosensors described in Prior Art 2 irradiate a photonic crystal substrate on which a gold thin film is formed, with light, and measure reflected light reflected at the photonic crystal substrate, thereby to detect the target substance, measure the concentration of the target substance, and the like. Patent Literature 1 (herein after, Prior Art 1) describes a biosensor having a reflection surface on which columnar protruding portions are uniformly arrayed in a square lattice shape, that is, in an arrangement having one rotational symmetry, as an uneven structure. Non Patent Literature 2 (hereinafter, Prior Art 3) describes a sensitivity figure of merit FOM1 and a sensitivity figure of merit FOM2, as performance indexes of sensitivity.